The Collaborative International Dictionary of English v.0.48:

Curio \Cu"ri*o\ (k?"r?-?), n.; pl. Curios (-?z). [Abbreviation
   of curiosity.]
   Any curiosity[3] or article of virtu; any object esteemed for
   its unusual nature.
   [1913 Webster +PJC]

         The busy world, which does not hunt poets as collectors
         hunt for curios.                         --F. Harrison.
   [1913 Webster]

WordNet (r) 3.0 (2006):

curio
    n 1: something unusual -- perhaps worthy of collecting [syn:
         curio, curiosity, oddity, oddment, peculiarity,
         rarity]